Glowworm boiler pressure jumping around

[Plumberhelp]

Hi all,
My Glowworm boiler dropped to 0.0bar. I topped up the system to repressurise it, but the digital display is just flashing and jumping all over the place from 0.3bar to 1.7bar, to. 05 bar to 2.2bar etc.

As a bit of background, the system seems to lose pressure and has been topped up every month or so over winter (it was never like this before so don't think that is normal). I had someone take a look at Christmas and they replaced the sensor as they said it was likely faulty. But the system is still losing pressure.

Rads have all been bled, no obvious leaks. Is there anything I am missing? What else is it likely to be causing this?

Glowworm boiler was installed in 2019.
Thanks

 

[Stuckinarut]

Have someone check for an expansion related issue and revisit that sensor.

 

[Plumberhelp]

Thanks @Stuckinarut .

Do you know if an expansion related issue is expensive?
I think I may have it under warranty. Any idea if this sort of thing would be covered?

 

[Stuckinarut]

Thanks @Stuckinarut .

Do you know if an expansion related issue is expensive?
I think I may have it under warranty. Any idea if this sort of thing would be covered?

Hard to say, if the vessel is flat unsure, but if needs replacing quite possibly. As for cost, again - depends if it needs recharging or renewal.

 

[Madrab]

+1 - An expansion vessel failure should be covered under warranty - as long as the service schedule is up to date.

A vessel that needs re-charged would indicate that it maybe hasn't been regularly serviced properly as that should be a yearly service check and wouldn't be covered under the warranty.

 

[Plumberhelp]

Thanks @Madrab.
It has been serviced every year, accept 1year during covid (I hope they honour the warranty).
So if it's the vessel should this have been picked up in my recent service in December?

 

[Madrab]

Thanks @Madrab.
It has been serviced every year, accept 1year during covid (I hope they honour the warranty).
So if it's the vessel should this have been picked up in my recent service in December?

Depends - if the vessel just needs re-pressurised then unlikley it dropped all it's pressure in 2 odd months, so I would have expected the pre-charge to have been low at that point. If it's failed then it could have failed the day before the pressure started to fluctuate.
That being said, an EV problem would usually manifest itself as a constant rise in pressure when the CH was on, up and over 3 Bar, when it cools down then it would drop to 0

If the pressure jumps all over the place then that could indicate something else, Does the boiler sound strange when the pressure starts to jump about?

they replaced the sensor as they said it was likely fault

That would normally have been a warranty job too.